The light-emitting principle of an OLED (Organic Light Emitting Diode) device is that, by means of applying a certain electric field to an anode and a cathode on two sides of an electroluminescent layer, electrons and holes, as being driven by the electric field, migrate to a luminescent layer from the cathode and the anode through an electron transport layer and a hole transport layer, respectively, and meet in the luminescent layer to form excitons and to convert light emitting molecules from the ground state to the excited state, which emits visible light through a radiation relaxation process. Compared with the conventional LCD (Liquid Crystal Display), an OLED display is increasingly applied in the field of high-performance displaying due to its characteristics such as self-luminescence, fast response, wide viewing angle, and capability of being fabricated on a flexible substrate.
When the display device described above performs displaying, it is possible to activate by inputting a square wave with a certain width to each row of pixels in sequence from the top to the bottom (or from the bottom to the top) through gate lines, and input a data signal for displaying to the pixels connected to the above activated gate lines through data lines.
In the prior art, in order to reduce manufacturing cost, a GOA (Gate Driver on Array) design may be adopted to integrate a TFT (Thin Film Transistor) gate switch circuit on an array substrate of an LCD display panel, so as to activate the gate lines on the array substrate.
However, since the OLED device is a current-type light-emitting device, when the OLED device performs displaying, the TFTs (Thin Film Transistor) connected to the activated gate lines in the pixel circuit need to maintain a turned-on state for a long time, so that a signal inputted by the data lines can be written into a driving transistor of the pixel circuit, and the OLED device is caused to emit light under driving of the driving transistor. Compared with the OLED display device, a backlight module of the LCD display can always provide a backlight source for displaying, thus the gate lines on the array substrate of the LCD display do not need to maintain an activated state for a long time. Accordingly, the GOA circuit integrated on the LCD display panel cannot be directly applied to the OLED display.